Assertion: Extra oxygen consumption in human, body is known as oxygen debt.
Reason: The extra oxygen is required by the body to oxidise the accumulated lactic acid produced during strenuous exercise.

If both assertion and reason are true and reason is the correct explanation of assertion.

If both assertion and reason are true but reason is not the correct explanation of assertion.

If assertion is true but reason is false.

If both assertion and reason are false.

Solution

If both assertion and reason are true and reason is the correct explanation of assertion.

During strenuous exercise, the muscle does not get sufficient oxygen to meet its energy needs immediately. So, it contracts anaerobically and accumulates lactic acid. During recovery, the oxygen consumption of the muscle far exceeds than that in the resting state. The extra oxygen consumed during recovery is called oxygen debt of the muscle.